FACADES NEED A STRONG DEFENSE, TOO:SILRES® BS SILICONE WATER-REPELLENT ADDITIVES

CREATING TOMORROW’S SOLUTIONS

WITH SILICONE WATER-REPELLENTTREATMENT, EXTERIOR COATINGS AREA MATCH FOR ANY WEATHER

ContentsLong-Lasting Coatings 3Economical Water Repellency 4SILRES® BS in Comparison 6Emulsions and Powders 7Proven Effectiveness 8Innovative Solutions 12WACKER at a Glance 13

3

Exterior coatings are more than just a display of architectural style. Theyprotect buildings from external forcesand thus play a large role in preserv-ing its value. The better a coating’sdefenses against every sort of weather,the longer it can fulfill its purpose.And that is the true meaning of eco-nomical.

Threefold EfficacyThe quality and cost-effectiveness of an exterior coating is evident in how wellit stands up to the weather and main-tains the breathability of the masonry.Coatings formulated with SILRES® BSsilicone water-repellent additives displayclear advantages in this regard becausethey work three ways: they increase thewater repellency and water resistance of the coating while simultaneouslyimproving its water-vapor permeability.

The Advantages Are Obvious:– Improved water beading– Moisture dries more quickly– Reduced microbial attack– Lower dirt pick-up– No pigment leaching– Paint does not fade– Longer-lasting coatings

Tried and TrueAs an ambitious partner for coatingsmanufacturers, WACKER SILICONESprovides a wide range of highly effectiveproducts. When we research, developand produce our SILRES® BS siliconeresin binders, primers and water-repellentadditives in emulsion or powder form,we pay particular attention to marketand customer demands. These productshave proven themselves over the yearsin a wide range of coating types. Ourcustomers can always count on expert,customized consultancy as well ascomprehensive technical service. We offer a local presence worldwide.

SILRES® and SREP® are a registered trademarks ofWacker Chemie AG.

4

Silicone additives are amazinglyefficient; even small doses optimizewater repellency in water-based coat-ings. Economy is boosted by thedurability of water-repellent coatings,thus greatly lengthening the intervalsbetween renovations.

Broad ApplicationsSILRES® BS water-repellent additivesare available as emulsions or powdersand render the pore structure hydro-phobic in a wide variety of water-basedcoatings. All of the pores are thereforewater repellent, but the material remainsbreathable and there is no film formation.SILRES® BS makes it possible to formu-late non-blocking coatings and prolongthe drying behavior of the paint whileremaining notably easier to process.

SILRES® BS water-repellent additives are highly effective in thefollowing coatings:– Silicone resin emulsion paints and

plasters– Silicate emulsion paints and plasters– Highly filled emulsion coatings– Emulsion-modified whitewashes– Interior paints– Stoppers– Adhesive coats– Aqueous facade primers– Mineral finishing plasters– Construction material mixes

of cement and/or lime– Insulation materials

5

Mineral AppearanceThe demand is increasing for matte,mineral-appearing coatings, such asSREP®s, that are both water repellent andwater-vapor permeable. To achieve thiseffect with emulsion paints, they must beformulated so that they are close to thecritical pigment-volume concentration(CPV). In highly filled emulsion paints, the lack of binder causes the formationof air-filled pockets. Because of theirmineral character, these paints appearporous and are water-vapor permeablebut not waterproof. With SILRES® BS,the necessary water-repellent effects can easily be achieved.

Water-Repellent Treatment of PorousCoatingsMineral organosilicate paints and plas-ters as well as emulsion-modified white-washes are naturally porous and there-fore allow water vapor to diffuse easily.Unfortunately, they are also very perme-able to water, which can lead to mois-ture penetration in the coating and sub-sequent damage. With SILRES® BSwater-repellent additives, the systemsremain breathable yet water repellent.This causes the facade to stay dryerlonger, and reduces dirt build-up, micro-bial attacks and salt damage. The coat-ing is considerably longer lasting and thefacade does not need to be renovatedas often.

ECONOMICAL WATER-REPELLENTTREATMENT

Environmental impact

Rain

Additive-free coating

Dirt build-upWater penetration

Water

Water and dirtbead off

Environmental impact

Rain

Coating with additive

Water vapor

Exterior coating without SILRES® BS water-repellent additive Exterior coating with SILRES® BS water-repellent additive

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Three types of additives are used torender coatings water repellent. A comparison of their efficiency, evenover a long period, shows the clearlead enjoyed by WACKER SILICONES’silicone water-repellent additives.

Water Repellency with Metal SoapsMetal soaps are fatty acid salts of metals;the most well-known types are stearatesand oleates. They are primarily used formaking plasters water-repellent. Theirinitial effectiveness is not maintained forlong in the system comparison, as theiraction is insufficient and not durable insome applications.

Water-Repellent RedispersiblePowdersThese powders are employed as bindersand evolve their hydrophobic effectsthrough active ingredients incorporatedinto the resin. The problem: the degreeof water repellency can be controlledonly by varying the amount of binderused.

Water Repellency with SILRES® BSTo let water-based coatings repel water,WACKER SILICONES developed aque-ous, solventless emulsions based onfunctional siloxane and a mixture of sili-cone resin and siloxane. Silicone pow-ders are ideal for use in every sort of drymix for powder, dry and pasty mineralcoatings. Both forms are usually incor-porated as the last formulating step;however, subsequent modifications arepossible.

FAR AHEAD OF THE COMPETITION

The Benefits of SILRES® BS Water-Repellent Additives:– Control over the degree of water

repellency– High hydrophobic effect– Extremely long-lasting effects– Economical use

Their unique chemical structureenables SILRES® BS silicone water-repellent additives in the coating toimpart the ideal combination of bead-ing effect and water-vapor diffusion.SILRES® BS products are available asemulsions or powders.

Functional Polysiloxane EmulsionsTheir amphiphilic character causes these solventless, water-thinnable emul-sions to focus on the coating surfaceand makes it water repellent. In contrastto unreactive methyl silicone fluids, theyare functional silicone fluid siloxanes with reactive groups.

Functional siloxanes have high sub-strate activity (adhesion promoters) andquickly spread out into layers of molecu-lar dimensions. This imparts typical sili-cone properties to the coating surface:water repellency and reduced adhesionof tacky substances, such as grime.

Functional groups intensify this effect.The hydrophobic methyl groups facingaway from the construction materialbring about the distinct beading effectand inhibit water penetration.

When thinned with water, this emulsionis also suitable as a water-repellentprimer of mineral substrates and for con-ferring water-repellent impregnation onfactory-made insulation.

Silicone Resin/PolysiloxaneEmulsionsThe chemical structure of water-thinnablepolysiloxane emulsions confers excellentwater-repellent effects on organosilicateemulsion paints and plasters. The methylgroups orient themselves away from the substrate and reduce the materials’wettability by water.

SILRES® BS PowderSilicone powder has a high active con-tent, is non-redispersible and is ideal forthe water-repellent treatment of mineralconstruction materials. In contrast toother powders, SILRES® BS does notcontain any emulsifiers or protective col-loids. This has the advantage of prevent-ing the incorporation of any additionalsurfactants. This makes it possible toachieve optimum water repellency andwater resistance.

The neutral, inert carrier in silicone pow-der prevents unwanted chemical andphysical effects such as saponification orincreasing viscosity and therefore offersmaximum applicational reliability.

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IDEALLY FORMULATED AS EMULSIONSAND POWDERS

SILRES® BS silicone water-repellentadditives let coating surfaces ward offwater permanently.

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Empirical experiments and practicallong-term trials prove that SILRES®

BS imparts excellent water-repellencyeffects in a wide variety of coatingsystems. WACKER SILICONES’ tech-nical service team would be happy to answer any inquiries regardingoptimum formulations.

The following experiments are limited to the use of SILRES® BS for internalwater-repellent treatment in which thewater-repellent additive is incorporatedinto the formulation. They demonstratehow the addition of even very smallamounts of SILRES® BS to various con-struction material mixtures drasticallyimproves water resistance.

SREP®s and Silicone Resin PlastersExperiments have demonstrated justhow much the hydrophobic properties of SREP®s and silicone resin plasters can be improved through the addition of a functional polysiloxane water-repellent additive. These tests involved SREP® formulated with and withoutSILRES® BS 1306 (1% by weight).

Results:– No change in the SREP® physical

properties – Excellent, long-lasting beading effect

during weathering– Low dirt build-up thanks to very high

water repellency

SILRES® BS in SREP®s

SREP® Additive-free With SILRES® BS 1306

Capillary water absorption, w24 value [kg/m2h0.5] 0.10 0.10

Water-vapor permeability, sd value [m] 0.076 0.069

Abrasion cycles, 4 d storage 4,300 4,400

1,000 h QUV-B beading behavior Good Very good

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Silicate Emulsion Paints and PlastersTheir structure makes silicate emulsionpaints and plasters highly permeable togases and water vapor, which is oftenvery advantageous physically. In temper-ate and cool climate zones, however, thecapillary water absorption is even moreimportant: it plays a role in determiningthe coating’s functionality and life span.Thus, the coating system structure doesresult in one disadvantage: the paintsand plasters are often open-pored withcapillary action and therefore tend toabsorb water.

Using SILRES® BS 50/1306 hasnoticeable benefits:– Drastically reduced water uptake– High water resistance even after long

storage periods – No deterioration of breathability

PROVEN EFFECTIVENESS IN EVERY COATING

Capillary water absorption of silicate emulsion paint with and without SILRES® BS

Untreated

w24

valu

e (k

g/m

2 h0.

5 )

Sand-lime brick

+ Additive-free silicate emulsion paint

+ Silicate emulsion paintwith 1% SILRES® BS 50

+ Silicate emulsion paintwith 1% SILRES® BS 1306

6

4

2

0

CPV 75%

w24

valu

e (k

g/m

2 h0.

5 )

0 %SILRES® BS 1306

1 %SILRES® BS 1306

2 %SILRES® BS 1306

3 %SILRES® BS 1306

CPV 70%

1.2

1.0

0.8

0.6

0.4

0.2

0

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Emulsion Paints and PlastersHighly filled emulsion paints are open-pored and absorb by capillary action,which causes increased water uptake.Even small doses of SILRES® BSimprove water repellency withoutdisrupting gas permeability.

Emulsion-Modified Whitewashes and PlastersEmulsion-modified whitewashes andplasters are very porous and water perme-able. When facades are coated withthese systems, an additional coating isabsolutely necessary for subsequentwater-repellent treatment. One alterna-tive is using SILRES® BS 1306 to adaptemulsion-modified whitewash systems.Only >1% is needed to achieve goodwater repellency.

Capillary water absorption of emulsion paint with and without SILRES® BS

Capillary water absorption of emulsion-modified whitewash with and without SILRES® BS

Untreated

w24

valu

e (k

g/m

2 h0.

5 )

Sand-lime brick

+ Additive-free + 2% SILRES® BS 1306 + 3% SILRES® BS 1306

6

4

2

0

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Mineral CoatingsSILRES® BS powders have proventhemselves as water-repellent agents forconstruction material mixes of cementand/or lime. They noticeably enhancewater repellency and water resistance indry plasters, grout mortars, stoppersand powder paints.

The Advantages:– Low water absorption coefficients– Less likely to get dirty– Long shelf life– Less product required

Modifying Interior PaintsModification with SILRES® BS productsalso offers indisputable advantages forpaints used indoors. They make it possi-ble to formulate non-blocking coatingsthat can be processed quicker and moreeasily. These coatings are also easier toclean and are therefore longer lasting.

Capillary water absorption of patch andrepair mortar with and without SILRES® BS

Additive-free

w24

valu

e (k

g/m

2 h0.

5 )

+ 0.3% SILRES® BS Powder A

1.0

0.8

0.6

0.4

0.2

0

Capillary water absorption of stopperwith and without SILRES® BS

Additive-free

w24

valu

e (k

g/m

2 h0.

5 )

+ 0.3% SILRES® BS Powder A

0.25

02

0.16

0.1

0.05

0

Capillary water absorption of mineral fin-ishing plaster with and without SILRES® BS

Additive-free

w24

valu

e (k

g/m

2 h0.

5 )

+ 0.3% SILRES® BS Powder A

1.0

0.8

0.6

0.4

0.2

0

Capillary water absorption of groutmortar with and without SILRES® BS

Additive-free

w24

valu

e (k

g/m

2 h0.

5 )

+ 0.1% SILRES® BS Powder A

+ 0.3% SILRES® BS Powder A

2

1.5

1

0.1

0.5

0

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BEING ACCESSIBLE TO CUSTOMERS ISTHE BASIS OF INNOVATIVE SOLUTIONS

Additional InformationThis brochure has shown you whatSILRES® BS can achieve as a water-repellent additive for silicone resin emul-sion paints and plasters. To find outmore about SILRES® technical data,please ask for our product data sheets.WACKER SILICONES can, of course,offer much more for masonry protectionwith silicones. For our complete productrange in this area, see our productoverview. We will be glad to send you a copy upon request. Or just visit usonline at www.wacker.com/silres

Customized ServiceUnique challenges require unique solu-tions. That’s why our technical servicemanagers are here for you personally.They understand your production andrequirements and know our productsand their wide range of benefits.

With this background, we can find exactlythe solution you need. Just call us. We will be glad to help you, no matterwhere you are.

WACKER SILICONES Services:– Technical service– Inspection and testing of coatings

with and without SILRES® BS– Selection of the appropriate additive

and the right dosage

In 2003, WACKER SILICONES launchedits “We Help Facades!” initiative, whichaims to provide detailed information aboutsilicone resin emulsion paints (SREP®s).Targeting a diverse range of groups, thewww.srep.com internet forum explainseverything you need to know about siliconeresin emulsion paints and facade protec-tion. Paint manufacturers are always welcome as collaborative partners – andthey profit from the initiative’s varied communications activities.

Just get in touch!

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Wacker Chemie AGHanns-Seidel-Platz 481737 München, GermanyTel. +49 89 6279-0info.silicones@wacker.com

www.wacker.com